Saturday, May 03, 2008
PLA Corner bracket failure mode
Looks like we have a failure mode for PLA corner brackets. This picture shows a relatively recent bracket torn apart by the forces of fitting an 8mm rod into it and over-tightening one of the grub screws.As you can see, the break is hardly a neat delamination, and the line of separation is at the apex of a teardrop-shaped hole. The corners also have little plastic in them, even after being squared off so they parted easily too.
As a temporary solution I am putting bolts through empty holes to hold things together. We'll see how it goes, but I think we may need to remove some of the unwanted honeycombing from the design and beef it up a little. I'm also installing the next one upside-down, so the apex of the teardrop is at the bottom of the bracket.
Vik :v)
Labels: corner bracket, failure, pla, reprap
